In a landmark 6-3 ruling, the Supreme Court on Thursday upheld the Affordable Care Act’s insurance subsidies in every state.

The decision in the King v. Burwell case is a win for the White House. For Justice Antonin Scalia, who wrote the dissenting opinion, the majority opinion, which was authored by Chief Justice John Roberts, is a “defense of the indefensible.”

He continued: “Rather than rewriting the law under the pretense of interpreting it, the Court should have left it to Congress to decide what to do about the Act’s limitation of tax credits to state exchanges,” Scalia wrote.

The ruling rejects a lawsuit that aimed to gut federal health-care subsidies for people in 34 states. If the Court had ruled the other way, more than 6 million people would have been at risk of losing their coverage.

Scalia was joined by justices Clarence Thomas and Samuel Alito in his dissent. Scalia took issue with the majority’s interpretation of the language within the Affordable Care Act. The law states that in order for people to qualify for health care subsidies, they need to be “enrolled in through an exchange established by the state.” The majority upheld that by “state,” the law referred to individual state exchanges or exchanges set up by the federal government. Otherwise, the majority opinion stated, state exchanges would drown in a “death spiral.”

Roberts wrote that “it is implausible that Congress meant the Act to operate in this manner.”

“The Secretary of Health and Human Services is not a State,” he wrote.”Words no longer have meaning if an exchange that is not established by a state is ‘established by the state.'”

King v. Burwell was one of the biggest legal challenges to Obamacare since 2012, when the Court upheld Obamacare’s individual mandate. In the conclusion of his dissent, Scalia said the Court got it wrong both times—and that it has shown bias toward the Obama administration’s policies.